Parse proxy strings to array of objects

The goal of this module is to take in a string (user input, someone copy and pasting a large list of proxies) and parse it into an array of objects.

I appreciate any and all feedback, but I'm specifically interested in improving the stringToProxy function.

Namely I'm unsure about mutating the string parameter, seems like there could be a better solution. And the way I'm declaring the proxy at the beginning of the function feels wrong to me (using As) but I couldn't think of any better solution. I also feel as though I may be overusing string.split().

Thanks for your time!

Edit: Incorporated the url module as Nazar recommended. I'm happy with this solution but still taking feedback.

const { URL } = require("url");

interface Proxy {
    host: string;
    port: number;
    protocol: string;
    auth?: {
        username: string;
        password: string;
    };
}

function parse(string: string): Proxy[] {
    const rawArray = stringToArray(string);
    const fixedArray = rawArray.map((string) => fixProxyString(string));
    const proxyArray = fixedArray.map((string) => stringToProxy(string));
    return proxyArray;
}

function stringToArray(string: string): string[] {
    return string.trim().replace(/[ ,\n]+/g, ",").split(",");
}

function fixProxyString(string: string): string {
    return string.includes("://") ? string : `http://${string}`; //if user doesnt specify a protocol, default to http
}

function stringToProxy(string: string): Proxy {
    const url = new URL(string);
    return {
        host: url.hostname,
        port: url.port ? parseInt(url.port) : 80, //if proxy is 80 url will ignore it so i need to explicitly add it
        protocol: url.protocol.slice(0, -1), //removing the colon
        auth: url.username ? { username: url.username, password: url.password } : undefined
    };
}

export = parse;

Before edit:

interface Proxy {
    host: string;
    port: number;
    auth?: {
        username: string;
        password: string;
    };
    protocol?: string;
}

function parse(string: string): Proxy[] {
    const rawArray = stringToArray(string);
    const proxyArray = rawArray.map((string) => stringToProxy(string));
    return proxyArray;
}

function stringToArray(string: string): string[] {
    return string.trim().replace(/[ ,\n]+/g, ",").split(",");
}

function stringToProxy(string: string) {
    const proxy = {} as Proxy;

    if (string.includes("://")) {
        const [protocol, remainder] = string.split("://");
        proxy.protocol = protocol;
        string = remainder;
    }
    if (string.includes("@")) {
        const [auth, remainder] = string.split("@");
        const [username, password] = auth.split(":");
        proxy.auth = { username, password };
        string = remainder;
    }
    const [host, port] = string.split(":");
    proxy.port = parseInt(port);
    proxy.host = host;

    return proxy;
}

export = parse;

Usage:

const parse = require("parse-proxy");

parse(`1.1.1.1:80, 2.2.2.2:80, 3.3.3.3:80`)

//result
[
  { host: '1.1.1.1', port: 80 },
  { host: '2.2.2.2', port: 80 },
  { host: '3.3.3.3', port: 80 }
]

parse(`https://user:[email protected]:8080\nhttps://user:[email protected]:3128`)

//result 
[
  {
    protocol: 'https',
    auth: { username: 'user', password: 'pass' },
    host: '104.236.55.48',
    port: 8080
  },
  {
    protocol: 'https',
    auth: { username: 'user', password: 'pass' },
    host: '213.105.29.14',
    port: 3128
  }
]